The effect of parenteral nutrition with lipovenous or intralipid on the fatty acid composition of plasma and erythrocyte membrane lipids in very-low-birth-weight infants

The effect of two commercially available soya-oil emulsions, Lipovenous and Intralipid, on essential fatty acid status of plasma and erythrocyte membr anes (EMB) in very-low-birthweight (< 1 500 g) infants was investigated for 10% and 20% solutions, respectively (N = 10 for each group). Fat emulsions were infused for a period of 6 days at a rate of 1 g fat/kg/d from day 3 a fter birth, and increased by 0.5 - 1.0 g/kg/d to a maximum of 3 g/kg/d at d ay 9. The fatty acid response to total parenteral nutrition revealed no maj or differences between Lipovenous and Intralipid. The plasma phosphatidylch oline (PC) omega 6/omega 3 ratio increased less in the Intralipid group, ma inly because docosahexaenoic acid (22:6 omega 3; DHA) decreased more after Lipovenous infusion, irrespective of the concentration of the lipid emulsio ns. Linoleic acid and alpha-linolenic acid present in the fat emulsions wer e incorporated into plasma and EMB PC, with concomitant decreases in their respective long-chain essential fatty acid metabolites, arachidonic acid (2 0:4 omega 6; AA) and DHA, irrespective of the type of lipid emulsion infuse d; The triene-tetraene ratio was significantly reduced after 6 days in plas ma PC, but was not affected in the EMB lipids. Owing to the similarity betw een Lipovenous and Intralipid there is a pressing need to optimise the comp osition of these lipid emulsions so that the possible negative consequences of decreased AA and DHA during total parenteral nutrition can be prevented .